Logical & analog axis

[froggy.sim-fr]

Is there any way to define logical conditions with flags to have an analog axis and on other way (if flag is false) not have analog axis.

Besides Flag should not use S3 or T7 or T8 (/U/M/D/I/O) but other conditions !
(because these flags already used by other functions/ flags)

eg :
DEF X1 X10 AND ( S4 OR T6)
REM whatever is X10

I'd like to have RNG as analog only if X1 is true, AND
RNG not analog with X1 = false

Is it possible ?

--------EDIT
Found myself that one, simple :

RNG /U Up
/M ^ REM : produces analog outpout
/D Down

OK; but is there not any cases (absolutely sure) where RNG /U wil not produce analogic output simultaneously with the Up digital output ? Is there to Lock that axis ?